MR microscopy may contribute to understanding what happens when a foreign body is place in the body for purposes of either imaging or measuring the chemical environment. We will image, with implanted coils, the development of fibrous capsule on the silicone coating that surrounds the imaging coil. Imaging will be done at 1, 7, 14 and 28 days after implant. Following fixation, the coil and surrounding tissue will be removed and imaged ex vivo at higher resolution. Finally, the complex of fibrous capsule and coil will be imaged by conventional microscopy.